The invention relates to windows and provides a window assembly which is particularly suitable for use as a secondary window, that is to say a window assembly designed to be fitted internally of the existing, primary windows of a building, so as to provide double glazing without the necessity of replacing the primary windows. It is desirable for such secondary windows to be unobtrusive, to provide a good seal in order to give the benefits of double glazing, and yet to be openable for cleaning and for ventilation. Various types of secondary windows are in common use but all have certain disadvantages.
In the simplest form of secondary window, the glass panel is simply clipped into a frame and must be bodily lifted out of the frame for cleaning and ventilation. Not only is this inconvenient but there is obviously considerable risk of breakage. Some secondary windows are side hinged in similar manner to primary windows but while this may be convenient for cleaning and ventilation the fixed and movable frames require to be fairly substantial and, due to its weight, there is a practical limit to the size of such a window. Vertically or horizontally sliding secondary windows are also commonly employed, but here there may be difficulty in cleaning the windows.
The present invention sets out to provide a window assembly which allows, in a convenient manner, great variation in the form of ventilation provided by the window, ease of operation, and ease of cleaning. Although the invention is particularly suitable for secondary windows, it will be apparent that the arrangement may also be used for primary windows if required.
The assembly according to the invention may be mounted in a vertical plane, in the normal manner of a primary or secondary window, but it may also, if required, be mounted at an angle to the vertical, or horizontally, for example when used s a skylight.
Although throughout this specification the expression "window assembly" will be used, for convenience, it will be appreciated that the invention is not limited to arrangements in which the vent is transparent or translucent, and is equally applicable to assemblies where the movable vent is opaque, for example for use as a ventilator or shutter. It is to be understood, therefore, that the expression "window assembly", where used in this specification, includes such arrangements.